老年痴呆症 z-bo 2020-10-26 338

　　Researchers at the University of Chicago proved that the types of bacteria present in the intestines affect the development of Alzheimer's disease in mice. Research published in the Journal of Experimental Medicine on May 16 found that long-term antibiotic treatment reduces inflammation by changing the intestinal microflora, thereby slowing the growth of amyloid plaques in the brains of male mice. It shows that it can be done, but it will not affect the same female mice. The bacterial community of the gastrointestinal tract (intestinal microflora) is usually harmless, but because it affects the activity of the human immune system, these bacteria also affect many diseases, even distant tissues.

　　Sangram S, Director of the Center for Molecular Neurobiology, University of Chicago. Professor Sisodia explained: “Recent evidence suggests that Enterobacter may play an important role in a variety of neurological diseases, such as autism, multiple sclerosis and Parkinson’s disease. Alzheimer’s disease. "Alzheimer's disease is characterized by the formation of amyloid plaques and the activation of immune cells present in brain microglia. These cells help get rid of amyloid plaques, but their activation can also aggravate the disease by causing nerve inflammation.

　　The intestinal flora of Alzheimer's disease patients has changed. Sisodia and his colleagues previously reported that gut bacteria can affect the development of these symptoms in rodents. Long-term antibiotic treatment limits the formation of amyloid plaques and reduces microglia activation in male (non-female) mice that express mutant proteins associated with familial Alzheimer's disease. "Although convincing, our published research on the role of intestinal flora in the formation of amyloid plaques is limited to one type of mouse," Sisodia said. In this new study, Sisodia and his colleagues studied the effects of antibiotics on appS1-21, another mouse model of Alzheimer's disease. Long-term treatment with mixed antibiotics can again reduce amyloid plaques in male mice, but does not affect female mice. Antibiotic treatment also appears to change the activation of microglia in male mice, from a form believed to promote neurodegeneration to a form that helps maintain brain health. To prove that the improvement in Alzheimer's disease symptoms is caused by changes in the intestinal flora, the researchers transplanted untreated mouse feces into antibiotic-treated animals. This process restores the intestinal flora, leading to increased formation of amyloid plaques and activation of microglia.

　　But why does the change of intestinal flora only affect male mice? Sisodia and his colleagues found that long-term antibiotic treatment changes the gut bacteria in male and female mice in different ways. Due to changes in the flora of female mice, the immune system produces more pro-inflammatory factors, which may affect the activation of microglia. "Our research shows that antibiotic-mediated interference of the intestinal flora has a selective and gender-specific effect on the formation of amyloid plaques and the activity of microglia in the brain." Mr. Sisodia said. "I want to investigate whether these results are due to changes in certain types of bacteria."